In RichDiesel's famous tutorials he says that door switches (the kind that everybody does a brush swap out for to change from 'off' to 'on' and back) can be done easier with a script, but I haven't been able to find an example--even in the JO/JA stuff. Does anyone know what he was talking about? Is it possible to use an animated shader to accomplish this? Or is a brush swapout the only way to change the texture?

A func_usable has a function to freeze an animated shader, and when used, switch to the next anim stage. Thus, you can easily build for example the code screens that can have for example 4 different symbols and you must type the right one to open some door (like in the first JO SP level).

However, it's not necessarily a great way to do a switch, since I don't think anim stages support different glows for each anim image. Thus, it would make quite a dull switch. It's really easy to have two func_usables in the same place, the other turned_off (invisible) and the other on. You can use a far more complicated and pleasant switch shader that way.

I have fancied building a multi-level scripted elevator with the floor number (up to eight) showing on one screen (using these switchable anim stages), and a button next to it would then launch the elevator to whatever floor number the player had happened to leave on that screen. That would be kind of cool. Too bad I have no map in which to use such an elevator...

If you can make that elevator that would be really good. I know a few maps where i would like to use it, if only i knew how. Maybe you could make a tutorial about how to make it. The way i know how, it would take me 22 different scripts to make that, and that does not seem all the nice. The problem i have is that when you call the elevator to the level where the button is pressed, it would need a diff script for each level because the possitions would be different. If there was a command that allowed you to know weather a button was being used, then it would cut things down, but i dont know if there is one

Yeah. I wouldn't need more than two or three scripts for it, and they would be pretty simple scripts. The reason I haven't done it or written a tutorial (beside the reason I haven't had a map requiring such) is that it might not work in MP. Of course, I map only SP, and so it wouldn't matter to me personally whether it works in MP or not, but I don't know if it is worth a tutorial without MP compatibility.